Method of regulating pumps of certain types for the pumping of liquids.



H. M. & T. M. CHANGE.

METHOD OF REGULATING PUMPS OF CERTAIN TYPES FOB. THE PUMPING 0P LIQUIDS.

APPLICATION FILED MAR. 22, 1911.

Patented July 9, 1912.

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H. M. & T. M. CHANGE.

METHOD OF BEGULATING PUMPS OF CERTAIN TYPES FOR THE PUMPING 0F LIQUIDS.

APPLICATION FILED MABHZZ, 1911.

Patented July 9, 1912.

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HENRY lvL CHANGE AND THOMAS M. CHANCE, OF PHILADELPHIA, PENNSYLVANIA;

METHOD OF REGULATING PUMPS OF CEBJTATN TYPES FOR THE PUMPING OF LIQUIDS.

Application filed March 22, 1911.

To all whom it may concern:

Be it known that we, HENR M. CHANCE and THOMAS M. CHANGE, of the city ofPhiladelphia, county of Philadelphia, anl State of Pennsylvania, haveinvented a new and useful Method of Regulating Pumps of Certain Typesfor the Pumping of Liquids, whereof the following is a specification,reference being had to the accompanying drawings, which show forms ofapparatus adapted to carrying out our method.

By the term liquids, we mean to include not only simple liquids, butalso mixtures of liquids, mixtures of liquids and gases, and suchmixtures of liquids and solids as are capable of being pumped.

The types of pumps or compressors to which our method is applicable arethose in which as an incident to the pumping operation, energy stored inan accumulator during the power or out-stroke of the pumping element, isemployed to effect or aid the return stroke. A method of pumping inwhich this method of regulation may be employed, is described in anapplication filed by us simultaneously herewith, being Serial No.616,080, but our invention is not limited to the method set forth insaid application.

The characteristic feature of our present invention may be explained asfollows hen a confined body of liquid is acted upon by a power impulseapplied to one end and by its movement effects pumping, and also at whatmay be termed its other end transmits energy to an accumulator, whichpower is utilized in efi'ecting the return movement of said body ofliquid, a definite time is required for each complete cycle comprising apower or out-stroke and a r turn stroke. This time element is fixed bycertain conditions among which are the volume and length of the body ofliquid, so that a normal period of oscillation of said body may be saidto exist. Thus, the number of cycles per unit of time may increase ifthe power is increased, or if the body of liquid be reduced in length,or increased in cross sectional area, and vice versa. In order to obtaindesired conditions of operation of the prime mover, it is important toregulate the action of such a moving body of liquid actuated from theprime mover, but regulation by modifying one or more of the abovedescribed factors involves relatively large changes in the operativeconditions, in

Specification of Letters Patent.

Patented July 9, 1912,

Serial No. 616,079.

* order to effect relatively small changes in the frequency of thecycles. Thus, to re duce the speed of a given body of liquid one-half,the power must be reduced to about one-fourth, or the body of liquidmust be increased in length about four times, or decreased in crosssectional area to about one-fourth. It is evident that these methods arenot well adapted to regulate such pumping operations, and to at the sametime preserve conditions favorable to high efliciency, for if the primemover be designed to Work with maximum eiiiciency for a certain power,velocity and amplitude or stroke, changes in any of these will beattended by loss in efficiency.

Our invention consists in a method of regulating the pumping action byalternately greatly retarding or even actually stopping actuation, andagain starting it at some selected point in each cycle, the timeinterval between such stopping and starting being thus added to the timerequired for the completion of each cycle. The point selected for suchstopping and starting is preferably at the commencement of the return oriii-stroke of the body of liquid, the condition of equilibrium existingthroughout the system at the moment of reversal being favorable to theoperation of the apparatus, which are conveniently employed for carryingout the method.

Our method of regulation may be carried out by a great variety ofmechanical contrivances of the escapement type acting upon theoscillating body of liquid in such manner as to control its movement.These appliances for instance, comprise valves, cocks, piston-controlledports, ported pistons or other devices, in common use, for controllingthe flow of liquids, as well as mechanical escapements operative-lyconnected with the oscillating body of liquid.

In the accompanying drawings, Figures 1, II, III, IV, and V, illustrateelementary devices of the first class just mentioned, and Fig. VI,illustrates a device of the second class. In said drawings, Fig. I, is avertical longitudinal section through that portion of a pumpingapparatus of the type just mentioned, in which the devices adapted tocarry out our method are located. Fig. 11, is a sectional detail viewedon an enlarged scale, illustrating the combined check and regulatingvalve shown in Fig. I. Fig. III, represents modified form of apparatus,

and is a vertical longitudinal section through that portion of theapparatus which comprises the device for carrying out our method. Fig,IV, is a vertical longitudinal section showing another modified formthereof located in the pump chamber of the pump, said figure alsoshowing the adjunctive parts comprising a conduit accumulator anddischarge main which constitute a type of the apparatus in its entirety.Fig. V, is a vertical longitudinal section showing another modified formthereof. Fig. VI, is a vertical longitudinal section, showing theessential portion of an apparatus oi the second class above mentioned.

Referring now to Fig. I, it will be understood that the portion of theapparatus there shown, comprises the end of a conduit adapted to carryout the general method of pumping by the movement of a confined body ofliquid, the portion represented in the drawing being the end which isremote from the point of application of power to the body of liquid, andwhich is adjacent to and connected with the accumulator. T he parts notshown in the drawing may be of any construction adapted to carry out thegeneral method of pumping, but they are preferably such as are describedand shown in our application filed simultaneously herewith. In saidfigure, 1, represents a portion of the conduit adapted to contain theconfined body of liquid, and which is in communication at the remote endwith means for application of power to the body of liquid, and at someintermediate point with the discharge for the pumping operation. 2,represents the accumulator which may be an air chamber, column of liquidor any equivalent device adapted to be made operative by means of theflow of liquid through the passage 3. 4, represents the piston by whicha portion of the energy derived from the movement of the confined bodyof liquid in the conduit 1, is transmitted to the body of liquid (orair) in the chamber 5, beyond the annular partition 6. The piston 4,operates in a cylindrical casing 7 in which it fits snugly, but so as tobe movable freely under the impulse transmitted to it, either by meansof the pressure of the liquid in the conduit 1, or by means of the rod8, which may be connected with a power piston located in said conduit.The casing 7, is provided, upon the side which is to the right of thepartition 6, with a plurality of ports 10, arranged at differentlongitudinal distances from the end of the cylinder, as shown, all ofwhich communicate with the interior of the chamber 5, and is alsoprovided at its extremity with a discharge pipe 11, whose opening is controlled by means of a valve 12, the details of which are shown in Fig.II. Said valve 12, is mounted freely upon a vertical'spindle 13, whoseupper portion is screw-threaded as shown at 14, so as to engage with thecorre sponding thread in the block 15, located in the wall of thechamber 5. A hand wheel 16, is mounted upon the upper end of the stem13, so that the lowest position of the valve 12, with relation to theorifice of the pipe 11, may be regulated. Normally it is so set as tolimit the reflux, without permitting closure. As the piston 4, advanceswithin its casing, fluid within the right hand end of the casing 7, isdischarged through the ports 10, into the chamber 5, and thence throughthe passage 3, to the accumulator 2, with corresponding accumulation ofpressure therein. As the piston overruns the ports 10, it isincreasingly cushioned and after overrunning the extreme port, is stillmore powerfully cushioned by the resistance to the further outflow offluid aiforded by the relatively small outlet of the discharge pipe 11.,which continues until the piston comes to rest. Thereupon the fluid fromthe accumulator begins to exert power to effect the return stroke, butthe partial closure of the aperture of the discharge pipe 1]., by thevalve 12, now in its lowermost position, greatly retards this untilsuificient fluid has passed by this check valve to move the piston farenough to uncover the ports, after which the return stroke proceedsrapidly and normally.

Referring now to Fig. III, 20, is the end of a conduit adapted to carryout the general method of pumping by movement of a confined body ofliquid to which we have previously referred, only that end of theconduit which is remote from the point of application of power to thebody of liquid being shown. 21, is an accumulator, the passage of liquidfrom the conduit to the accumulator being controlled by the interposedcheck valve 22. 'This valve has a recessed valve stem 23, within whichis re ceived a boss 24, on the end of a rod 25,

mounted in the piston 26, which slides within the vertical piston casing27. The upper end of this piston casing engages with the conduit 20, bytwo passages, one of which, 28, is controlled by a regulating valve 29,while the other passage 30, is controlled by the check valve 31. Theoperation is as follows :The column of liquid moving forward in theconduit 20, under the impulse of the power stroke, opens the check valve22, and accumulates pressure within the accumulator, until equalizationof the pressure eflects closure of the check valve, at which time thepiston 26, is at its lowermost position, by reason of the pressure uponits upper end permitted by the passage of liquid through the channel 30,and check valve 31. As the pressure in the conduit 20, decreases,

the pressure within the accumulator operatmovement being retarded by thenecessary outflow of liquid from the upper end of the casing 27, throughthe passage 28, subject to the retarding action occasioned by theregulating valve 29, which introduces the desired time interval beforecontact of the boss 24:, with the top of the valve stem 23, elevates thevalve 22, permitting the pressure in the accumulator to drive liquidtherefrom into the conduit to effect the reverse stroke.

There is illustrated in Fig. IV, a device similar in some respects tothat shown in Figs. I, and II, with the difference that the retardationmeans are applied directly to the main actuator plunger of the pumpingapparatus. Here the plunger ll), operates within the casing d1, havingports 42, communicating with the pumping chamber 4L3, which leads to theconduit lt which is provided with an accumulator 85, and dischargeconduit 86. The intake 45, for the pumping chamber is controlled by thecheck valve 46. In addition to the ports 6L2, the casing 41, is providedwith an outlet 4C8, to the pumping chamber, governed by a check valve49,

and also with an auxiliary passage :7, which is governed by a regulatingvalve of the construction illustrated in Fig. II, and previouslydescribed. In operation, when the actuating plunger reaches the forwardextremity of its stroke, it overruns and thus closes the ports a2, andas the return stroke begins the check valve 4L9, also closes, so thatpressure in the casing l3, is at first communicated to the actuatingplunger only by way of the small passage 47, controlled by theregulating valve now in its lowermost position, which retards suchcommunication of pressure until the successive uncovering of the ports42, permits free communication between the pumping chamber 43, and thecasing 41, to effect the return stroke of the actuating plunger.

In Fig. V, there is shown a conduit 50, with a cylindrical extensioncontaining a piston valve 51, which controls the port 52, in the bypass53, of the conduit, which leads to the extension 54, and accumulator 55.The piston valve is cushioned between the opposing springs 56, and 57,which normally keep it in central position closing the port 52. Thepower impulse of the pump driving liquid in the conduit 50, operatingupon the end of the piston valve 51, drives it against spring 57, anduncovers the port 52, the liquid beyond it passing into the eX- tension54, by way of a passage 58, controlled by a check valve 59. As thevelocity of the moving liquid decreases, and the column comes to rest,the piston valve 51, returns to its central position under the influenceof the springs, closing the port. The check valve 59, having alsoclosed, the pressure within the accumulator can only operate to move thepiston 51, and again open the valve by means of the communica tionafforded by the passage 60, controlled by the regulator valve 61, whichretards the fiow of liquid sufliciently, and thus prevents the reversestroke, until the piston has again uncovered the port, when theunrestrained pressure of the accumulator permits liquid to fiow freelyback from the accumulator as the liquid in the conduit 50, makes itsfull return stroke. At the end of this stroke, the cushioning springsagain bring the piston valve 51, to its central position.

Fig. VI, shows an actuator plunger 67, working in a pump chamber 68, apiston rod 69, and cross-head 7 O, cross-head guide 71, a latch 72, insaid cross-head, operated by latch-spring 73, a latch releasing push rod7st, push-rod guide 7 5, a piston-rod 7 6, connected to a piston 7 7working in a cylinder 78, a check valve 7 9, and regulating valve 80,placed in an outlet overflow 81, in connection with a tank 82; and aconnection 83, between the cylinder 7 8, and pump chamber 68. When theplunger 67, moving from right to left completes its power stroke, thelatch 7 2, is in contact with the push-rod 7 41, and suction developedin the pump chamber 68, acting through the connection 83, upon thepiston 77, causes the piston 77 and pushrod 74t, to fall, and enablesthe spring 73, to push down the latch 72, engaging with the slot incross-head guide 71; after the end of the suction period reactionpressure from the accumulator acting through the pump chamber 68,through the connection 83, upon the piston 7 7 tends to force it and thepushrod 74, up against the latch 72, and raise this to a point where itis no longer engaged in the slot in cross-head guide 71, but this actionis delayed by the time necessary for liquid in one end of the cylinder78, to es cape through the regulating valve 80.

The construction shown in Fig. VI illustrates a type of apparatuswherein the return stroke of the body of liquid is controlled by themovement of the pump plunger 67. In carrying out our method by means ofapparatus of this type, we do not confine ourselves to the employment ofthe particular organization thus shown, but said figure is intended torepresent typically any apparatus wherein control of the plunger is themeans used to effect the regulation characteristic of our method.

In using our method of regulation it is best to employ devices whichexcept initially have small etiect upon the velocity of the returnstroke, and this can be accomplished by actually stopping theoscillating column, or by so shutting off the accumulator pressure thatthe body of liquid moves very slightly for a definite time interval ator about the commencement of the return stroke, and at the end of thisperiod quickly &

removing the obstruction to movement so that the return stroke proper ismade with practically its normal velocity. By this method of regulationpumps may be operated at a small number of strokes per minute withoutappreciable loss in efiiciency, for the conditions under which the powerstroke is made are not changed by thus varying the speed of operation.

Having thus described our invention, we claim 1. The hereinbeforedescribed method of regulating pumps, wherein power oscillation andreturn oscillation of a body of liquid are utilized to absorb and supplyenergy; which consists in restraining the return oscillation at or aboutits commencement and increasing the time interval between the completionof each power oscillation of the body of liquid and the completion ofits return oscillation, whereby the cyclic frequency of operation isdecreased.

2. The hereinbefore described method of regulating pumps, wherein poweroscillation and return oscillation of a body of liquid are utilized toabsorb and supply energy; which consists in restraining for a limitedtime the commencement of the return oscillation and increasing the timeinterval between the end of each power oscillation and the commencementof the return oscillation, whereby the cyclic frequency of operation isdecreased.

The hereinbefore described method of regulating pumps, wherein themomentum of a moving body of liquid is utilized to draw any liquid afterthe direct action of the driving medium has ceased, and in which saidbody of liquid is driven in a return stroke by energy stored during thepower stroke; which consists in restraining said return oscillationduring an interval of time after the end of the power stroke and therebydecreasing the cyclic frequency of operation.

In testimony whereof, we have hereunto signed our names, atPhiladelphia, Pennsylvania, this twentieth day of March 1911.

HENRY M. CHANGE. THOMAS M. CHANCE.

WVitnesses JAMES H. BELL, E. L. FULLERTON.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

